Roll rate P47 VS FW190

Discussion in 'Aviation' started by pinsog, Oct 30, 2009.

  1. pinsog

    pinsog Member

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    Which had the faster roll rate P47 or FW190? I tend to believe the P47 did, but does anyone know for certain?
     
  2. drgondog

    drgondog Well-Known Member

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    #2 drgondog, Oct 30, 2009
    Last edited: Oct 30, 2009
    The Fw 190 out rolled the 47, the 51, the 109, the Spit at low to medium speeds. IIRC at 250mph it had a rool rate nearly 150 degrees per sec, the 47 was near 95-100, the 51 around 90 and the 109 around 75-80 degrees per sec.

    At high speeds the P-47 and P-51 gained rapidly, still maintaining their roll rates but the Fw 190 dropped away - below the 47 and 51 at around 325Kts.

    I will have to dig to recall the charts of roll rate vs airspeed.
     
  3. marshall

    marshall Member

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  4. renrich

    renrich Active Member

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    The roll chart is certainly useful and demonstrates, at least to me, how misleading certain information can be. In Bob Johnson's book, "Thunderbolt" he said that the Jug could outroll a Spitfire and he used it's rolling advantage in mock dogfights. I had read in Dean, "America's Hundred Thousand," that the P47 was not known for being a good roller. Johnson said that when a Spitfire got on his tail, he would dive and roll. The chart shows that the Spitfire rolls really well until about 280 mph where the P47 begins to outroll it. That explains Johnson's tactics. In a dive, he was probably exceeding 280 mph plenty fast.
     
  5. Civettone

    Civettone Active Member

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    It depends which version. For instance the P-47N rolled better than the D.

    Oh and the Spit ... similar story. Which Spitfire? Which wings? Clipped or not ?

    Kris
     
  6. DAVIDICUS

    DAVIDICUS Member

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    #6 DAVIDICUS, Oct 30, 2009
    Last edited: Oct 30, 2009
    I believe the P-47 was well known for being a good roller and it is widely reported that the "N" rolled better than the "D".

    The F4U also rolled well. When rolling in conjunction with powerplant torque, in other words, rolling left, it was among the very fastest rolling fighters of the war. In the inventory of American fighters, only the P-47N rolled faster, and only by 6 degrees/second.

    Chance Vought F4U-4 Corsair



    The XP-47N took to the air for the first time on July 22, 1944. Test comparisons were made with a P-47D-30-RE throughout the early portion of the evaluation period. Much to everyone’s surprise, the XP-47N, with its greater wingspan and higher weight actually proved to have better roll performance than the D model. At 250 mph TAS, the N attained a maximum roll rate just over 100 degrees/second. The P-47D-30-RE could manage but 85 degrees/second at the same speed. At higher speeds, the N widened the gap further. In mock combat with a P-47D-25-RE, the new fighter proved to be notably superior in every category of performance. In short, the XP-47 waxed the venerable D model regardless of who was piloting the older fighter. The new wing was part of this newfound dogfighting ability, however, the more powerful C series engine played a role too. The additional horsepower allowed the N to retain its energy better than the older Thunderbolt. Perhaps the greatest performance increase was in maximum speed. Though not as fast as the stunning P-47M, the heavier N was fully 40 mph faster than the P-47D-25-RE and could generate speeds 30 mph greater than its principal rival, the Mustang. Scorching along at 467 mph @ 32,000 ft., the N could not be caught by any fighter in regular service with any air force on earth with the single exception of its M model sibling. This combination of wing and engine had pushed the N model up to the top rank of the superlative prop driven fighters then in existence.

    Seversky Aircraft and Republic Aviation



    Francis Gabreski also raved about the outstanding roll performance of the P-47. In fact, he said that rolling was a tactic used by P-47 pilots due to it's capabilities. If you do a web search for " P-47" and "roll" you will find more than a dozen accounts in just a few pages.



    Relevant to Bob Johnson's claim, there is an RAF Air Fighting Development Unit tactical trial between the P-47C and Spit Mk. IX that concludes:

    P-47C v. Spitfire IX --

    25. Manoeuvrability – The good aileron control gives the P-47 an excellent rate of roll even at high speeds, and during mock combats it was considered to roll as well as, if not better than the Spitfire at about 30,000 feet. At lower altitudes there is nothing to choose between them.

    P-47 Tactical Trials



    In other tests by the USAAF Proving Ground Command, it was concluded that:

    "The rate of aileron roll is the best found in any type of American fighter."

    P-47C Tactical Trials
    .
    .
    .
     
  7. renrich

    renrich Active Member

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    Interesting because data from NACA TR868 and Perkins and Hage show both the P40 and P40F to be much superior in rate of roll to the P47C1. Page 255 in Dean, "America's Hundred Thousand," P40 airplanes were particularly good in roll. An early model was shown in one report as having a maximum roll rate of 135 degrees per second at an indicated air speed of 360 mph. Later data show a P40F having a peak rate of 95 degrees per second at about 275 mph IAS. In any case pilots attested to high roll rates. For the P40C "It had an extremely high rate of roll" For the H87A/P40E "The rapid roll rate, the most delightful aspect of the P40" And other comments: "The extremely rapid roll rate-" "Roll are effortless" "Rolling performance was excellent; I think it was as good as any AAF fighter", "Rapid aileron response, by comparison the P51 was locked in cement" and " Roll was great".
     
  8. DAVIDICUS

    DAVIDICUS Member

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    #8 DAVIDICUS, Oct 30, 2009
    Last edited: Oct 30, 2009
    Interesting indeed.



    PROOF DEPARTMENT
    TACTICAL COMBAT SECTION
    ARMY AIR FORCES PROVING GROUND COMMAND
    EGLIN FIELD, FLORIDA

    FINAL REPORT ON TACTICAL SUITABILITY OF THE P-47C-1 TYPE AIRCRAFT

    18 December 1942
    ...
    6. DISCUSSION:
    ...
    (3) Maneuverability -- The P-47C-1 was flown in mock combat against the P-38F, P-39D1, P-40F, and the P-51.
    (a) It had superior rate of aileron roll at all speeds, and especially at high speed to all American fighter contemporary types, none could follow it in a fast reverse turn.
    ...
    (e) In close fighting the P-47C-1, due to its faster aileron roll, can quickly reverse turn and break off the combat almost at will.

    P-47C Tactical Trials
    .
    .
    .
     
  9. drgondog

    drgondog Well-Known Member

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    D - you do know the P-51 in those trials was the P-51A with the Allison which was slower in roll than the 51B?
     
  10. renrich

    renrich Active Member

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    Well, it all goes to show that the information we see bandied about can be inaccurate. Perhaps some of the discrepancies can be traced to the individual AC tested or perhaps that performance varied so much at different altitudes or I don't know. I saw the report of the comparison of the A6M versus various US AC and a number of the Army AC had mechanical problems which prevented from completing all the comparisons. The Zero kept chugging along though. Reminds me a little of comparing some Japanese cars with some US cars, especially a few years ago.
     
  11. Kurfürst

    Kurfürst Banned

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    Keep in mind the chart shows peak roll rates - roll acceleration is not shown, ie. the ability of the aircraft to roll quickly. This can be significantly different, as some aircraft were quick and brisk in their rolls, others were sluggish and lazy, and though eventually speeded up, this has of less practical use in combat.

    The practical rolling manouverability in combat is better gauged by time to bank figures, which would take into account the initial acceleration as well.
     
  12. renrich

    renrich Active Member

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    #12 renrich, Oct 31, 2009
    Last edited: Oct 31, 2009
    Kurfurst, thanks for your comment. A question I have, actually two, is: a plane must bank before it turns so I can see how the initial part of the roll is important. Quicker is better. The P38 had an initial resistance to roll so it did not turn very fast. Johnson, in his book, though knew he could not outturn a Spitfire so he rolled first one way and then the other while diving. What i gather from that is that it is better for the attacker's wings to be in the same plane as the plane being attacked. I don't really understand why that is an advantage, especially against an AC with all guns located near the center of the longitudinal axis. Another question is from the rolling point of view. Dean says that a four second 360 degree roll was good for a WW2 fighter. Obviously that is about 90 degrees per second. To me, the difference between say a 90 degree per second roll rate and an 80 degree per second roll rate would not be of great moment. The L39 has a roll rate of around 360 degrees per second. I once did a couple of aileron rolls at 250 knots IAS in one and that roll rate seems almost instantaneous. Watching film of a WW2 fighter in a 4 second 360 degree roll seems really slow. This post is reall y clumsy but I would enjoy any comments.
     
  13. Altea

    Altea Banned

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    #13 Altea, Oct 31, 2009
    Last edited: Oct 31, 2009

    First and foremost, the L-39 roll rate being really excellent, is not that excellent for sure!!!
    I can call my friend Sergei Burdin an instructor with 6500-7000 hours flight on that type to have more accurante datas, if you want so.:)

    It shows how difficult it is to estimate roll on nimble planes

    From pilots notes you roll at 400 km/h on that type. Even faster. Your aspect ratio is only 4.75 for a wingspan of 9.46, and see your aileron aeras. Maybe the wing tank plays is rule for pressure/lift conservation on wing tips. To resume, it'a short, square wing with big ailerons on it, and some device fighting against marginal pressure losses.. Nothing surprising, only logic for your fast barrels.
    P-47/F4U/P-38/F6F have a lot of planes parts with some weight far away from the GC. It's not good for inertia moments. Moreover if you compare the rolling wing to a turning windmill blade, it takes a cubic low for speed for a linear lengh increase. Applying that model, the 10% smaller wing should turn 33,1% faster using the same energy for that.

    BTW the best warbird "roller" from european collectors seems to be the Yak-11 (and so probably the 3). But it performs it at a much lower speed (250-300 km/h). You can easily see it from a flight demonstration at the Ferté Alais or Meulun-Villaroche with a good pilot on commands.

    Moroever; i dont think that "your" L-39 has a better roll rate than "my" Yak-55* ! :tongue1:

    *An old souvenir (1994...).

    Regards
     
  14. renrich

    renrich Active Member

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    The spec sheet I have on the L39 shows a RR of 300 degrees per second at 250 KIAS. Believe me that when I threw the stick hard against my leg it rolled plenty fast. Hard to tell without a stop watch but it seemed like almost gorrilla one.
     
  15. Civettone

    Civettone Active Member

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    Thankfully someone pointed this out !!!
    The same goes for the climb and turn rate. All you see charts or information about is about constant climbing/turning/rolling but not about the instantaneous climb/roll rate.

    This acceleration is sooo important but never gets much attention. I also believe that is what the real strength of the Bf 109 and Fw 190 was...

    Kris
     
  16. Altea

    Altea Banned

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    #16 Altea, Oct 31, 2009
    Last edited: Nov 4, 2009

    Ok, ok...So share your full spec sheet with us! It' from a great kind of interest as a "study subject" for short winged planes as I-16, Yaks, Laggs; 109s...


    There is moreover, not such an information in russian pilot's notes booklet about that, and you're the L-39 specialist here, not me.

    Regards
     
  17. billswagger

    billswagger Member

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    Its pretty much a no brainer. The FW190 was much better in roll at typical combat speeds and really only clipped wing spitfires came close to matching the rate of roll.

    I think the jug has its reputation for good roll performance because it was designed to fly at higher speeds where the ailerons were adjusted to still be able to respond even under moderate compressibility. Also the control feel in such rolls was said be comfortable where rolls in the P-51, and P-38 were said to be heavier above 300IAS. (save: until hydraulic s on the 38 were used)

    It is its ability to roll at high speeds where it was more impressive than a spitfire, and where the FW would lose roll performance. So perhaps that is where the myth is perpetuated. I just think that typical combat speeds were usually between 250-300IAS and any roll advantage would still be in an FW190s favor. Planes diving to get away might roll and maneuver to lose a tailing plane, so perhaps in this area of the envelope the two planes were more close in roll rate.

    bill
     
  18. barney

    barney Member

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    Rolling quickly just keeps you in the enemy's gun sight. Rolling is only useful in assuming the correct attitude for turning. So, rolling and turning are components of the same maneuver. In other words, if you have an aircraft that is good roller but a lousy turner, how fast the aircraft can roll doesn't mean much if all your enemy has to do is touch his rudder to shoot you down. So, I suggest, to be meaningful, the two in combination should be considered.
     
  19. timshatz

    timshatz Active Member

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    But there are also a bunch of different rolls. Snap roll, barrell roll, ect.

    I think you're talking about a slow roll. But something like a snap roll can be useful to get you out of the gunsight quickly. Kind of a horizontal displacement to one direction or the other.
     
  20. barney

    barney Member

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    No, I am thinking that in a defensive role you'd want the roll to be as fast as possible, remembering the pilot has to end the roll in the attitude he (mostly male pilots in the war) wishes to turn in. Then, in a coordinated effort, apply elevator to change direction. So, that, I believe, would be a snap roll.

    How quickly the result of those two actions in combination move your aircraft out of the aggressor's windscreen, I'm suggesting, should determine the effectiveness of the planes abilities, not just roll alone.
     
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